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Apply a function to every row of a matrix or a data frame
...pass additional arguments after FUN argument (as Dirk already suggested):
set.seed(1)
m <- matrix(round(runif(20, 1, 5)), ncol=4)
diag(m) <- NA
m
[,1] [,2] [,3] [,4]
[1,] NA 5 2 3
[2,] 2 NA 2 4
[3,] 3 4 NA 5
[4,] 5 4 3 NA
[5,] 2 1 4 ...
stl 字符串std::string作为std::map主键key的实例 - C/C++ - 清泛网 - 专注C/C++及内核技术
stl 字符串std::string作为std::map主键key的实例本文通过一个实例介绍std::map字符串作为key的常见用法，并使用find_if实现map按value值查找。代码如下：
#include <map>
#include <string>
#include <algorithm>
using namespace std;
class map_value_finder
{...
C++在堆上申请二维数组 - C/C++ - 清泛IT论坛，有思想、有深度
假设要申请的是double型大小m*n数组有如下方法方法一：优点：申请的空间是连续的 缺点：较难理解
double (*d)[n] = new double[m][n]复制代码
方法二：优点：容易理解 缺点：申请的空间不能连续且需要多个指针才能管理
double *d[m];
for...
How to create composite primary key in SQL Server 2008
...mns you wish to form as a composite key
Right Click over those columns and Set Primary Key
To see the SQL you can then right click on the Table > Script Table As > Create To
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Exposing a port on a live Docker container
I'm trying to create a Docker container that acts like a full-on virtual machine. I know I can use the EXPOSE instruction inside a Dockerfile to expose a port, and I can use the -p flag with docker run to assign ports, but once a container is actually running, is there a command to open/map addi...
Git diff --name-only and copy that list
...
@HalvorStrand, I haven't tested it, but setting IFS=$'\n' first may do it. (Preferably in a subshell so as not to mess up your original IFS value.)
– Wildcard
Nov 15 '17 at 7:57
...
How can I output a UTF-8 CSV in PHP that Excel will read properly?
...s:
header('Content-Encoding: UTF-8');
header('Content-type: text/csv; charset=UTF-8');
header('Content-Disposition: attachment; filename=Customers_Export.csv');
echo "\xEF\xBB\xBF"; // UTF-8 BOM
I believe this is a pretty ugly hack, but it worked for me, at least for Excel 2007 Windows. Not sure ...
How do I drop table variables in SQL-Server? Should I even do this?
... is a solution
Declare @tablename varchar(20)
DECLARE @SQL NVARCHAR(MAX)
SET @tablename = '_RJ_TEMPOV4'
SET @SQL = 'DROP TABLE dbo.' + QUOTENAME(@tablename) + '';
IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(@tablename) AND type in (N'U'))
EXEC sp_executesql @SQL;
Works...
How to display long messages in logcat
I am trying to display long message on logcat. If the length of message is more than 1000 characters, it gets broken.
10 A...
How can I rename a project folder from within Visual Studio?
...ht the project and press Alt+Enter or F4, or right-click > properties).
Set the property 'File Path' to the new location.
If the property is not editable (as in Visual Studio 2012), then open the .sln file directly in another editor such as Notepad++ and update the paths there instead. (You m...